The murders of billionaires Barry & Honey Sherman found dead in their mansion in Toronto by their realtor. They were found with their necks tied, fully clothed on their pool deck with no signs of a break in. Well known philanthropists, Barry was in the pharmaceutical industry and they donated millions annually to multiple charities. The police originally believed it was a murder s*icide and didn't pursue other leads.
The family launched a private investigation that found the evidence didn't support that theory and thus proved police incompetence.
As the public became more interested, it was discovered there was a whole family dispute over inherited shares of the apotex company. The Sherman's nieces and nephews had launched lawsuit over their right to inherit shares which they lost and most accepted.
The Sherman's children hired private investigators bc of the inept toronto police. It uncovered an unknown man leaving the property around the time of the murders.
The case is fascinating and is the subject of multiple podcasts, a book, and movie